Monitoring statistics behaviour for multichannel analysers with scintillation probes

Many territorial laboratories have generally a modest endowment concerning the measurement of radioactivity. Numerous such laboratories use only mono-channel analyzers with scintillation detectors, lead castles and standard sources. In case of long time measurements or of a big number of samples per day, the stability of the calibration parameters could be a problem. In this paper we present some practical methods of fast daily checking for calibration parameters of the mono-channel analyser. This checking consists in a series of short measurements for a standard source and the comparison of the results with the value from calibration standards. At significant deviations we make a fast correction of measurements parameters (actually of the high voltage supply) without making a new complete calibration. In this way we extended the interval between two complete calibrations at quarterly, in each season, or half a year (in the cold season and in the hot season). (author)